Preventing discoloration of fuel oil



- number of different chemical structures increase. 1;,

Patented June 9, 1953 i i =1 r 2,641,539 v PREVENTING nisoondRA'noN OF iUEL o'IL RalphuBrr-rfllhomlljsbmy Hinsdah and. JOSe1ili .A. Qhen ek, en envi 111., sassi norssto Uni..- vers al pi l lfroducts ucompany, Chicago, 111., a corporation of Delaware Na Drawing; Kpplicati'dii April 12; 1951), Serial No. 155552 10 claims. (0114. 73)

This invention relates to 'a novel methodpfp te- From the above description, it isapparent, that venting discolorationof fuel oils andmore parthe ,treatmerithof. fuel oils is..a..difficu1t.p b1e ticularly to the use of a particular additive .IniXr It hasloeen found that the use ofanyrgivenladdie ture in fueloils to prevent discolorationnther qi. tive ,orjeven a.mixturetof.two..additives,...WilL 19i The fuel oils to which the present application 5 serve. satisfactorily to. retard discoloration .oftaill isdirected, in eneral, comprise hydrooarbondise oreven.thegreaterportion 0f virginfuel oilsfrofn tillates boiling above the rangeof. the gasoline different. geographicsources, 0L cycle stock fuel and thus include particularlyokerosene, #1 fuel oils, or of blends jof.virgin andhcycle's'tooksk oil, #2 fuel oil, burner 011,. diesel oil, etc as ,well rsponseo'r susceptibility of fuelroil'srtoadditives as compositions containing .these oils such as jet varies'considerably dependinguponthe geo raphr fuels, tractor fuels, etc. These oils in. stora e, i'c sourceandthe typevofntreatment, v However, tend to undergo discolorationandturn. .,f17om a fo'rfianadditiv. foruse.infuel oilstto beooommerlight to a dark color. m Most consumers qbiec t y satisfactory, it must satisfy. the greater nor.- the dark colored oils and, therefdre;.wi1l.f1ot 9111f: ti'on. of commercial .fuel..oil's. regardless of. the chase the discoloredoils atrthenliemi m. prise sourcenr typeof treatment. The presentinvem normally prevalentnfor thelighticoloredpils. In tion.offers a novelnadditiveo mixture .which,,will fact, some of the,specificationsfor,theseoils in; satisfy a. largervarietyotcommercial.fuel.oils. elude aminimum color requirement which the ltiis readily appreciated that the use .ofnan darker oils eannot mfififi additive mixture as. propo'sedinthe presentinvenr tion will..find aready, acceptance in.the fueloil problem to the refiners,beausepf tlie industrytbecauserit willaccomplish.results ,which 'cornpos'ition. of fuel oils. nereinbefore J fit otherwise, .are not. obtainable, This will 1 proveto forth fuel pil's are higher toiling than gasoline be f,,great adv.anta e torefinersawhoatp esent and, bec u frth e higherbo g blf15i1 t i rei a n X 2 m dshiIJ.in retarding dismal: fuelyoils bontain a gher in; her and wid r as orati n offiuel; 9 1s. and h re o e... arehav n riety of difierei'it compounds. It is well known difficulty in satisfactorily marketing their fuel that, as theinolecular wei'gritprboiuri range oils.

a hydrocarbon distillate increases; the number of one. embodiment .the\=pres 1 t. is'ofi'iers of aparticiilar boiling range and tlie The treatment of fuel oilspl sents Further, fuel oils..varyr.cohsideraiblydepending ilp nthe. source of. he ude petroleumrthatris'. the composition of fuel oils varies considerably s-ito 'Q .91 l2h H TQ? Qft bfii illd i -M i .1

e aln s fiaem pd m hebr sent nvsli stillatipn ofcrucle oils amil hese r at i .m h ii dreami s plq auowt nibrilvrefrred to-in the artfa's' a fllel oil wni ch ooinprises adging..theretqa sta 1-, 11 due lpilizing amountcof an.additive miiitiire;oofnpris is-ll z- -t .s=e de i ibrq tte -e st lds-l M l a d an r ienolteli tqn ai as-f n about 2 to about 12 carbon atonis' per, molecule, m k 611 or as a c mpon'eiit infu'el' on is Qflan allpanpl .a ine..c ntaini from, about 8 Th terin cycle stock is used be f th 2. .0 a bo il an oil is separated from a fraction which is reoycled QIKYI rniiue containing fro naboutfi to. aljQiitQZO toth cracking process for further oon vers'ion carbonatorns per molecule and (4) a metal dether'e'in. Fuel oils derived from cyclestocks likeactivaton. .H a E Wise .eOniprise ,facomplexconfposition which. is w he additive niii ture of tlieipresentin dependentnponthfi .sourcepf theorieinal crude il inbfore stfdrtii isad p ed f r se Qil anti l pmwiie h rtthe.,cracki ii nonrtatar Wo d a t roftf i .r a 4 n lyt or catalytie as well as upon the severity of it. m; istl ecels's'aryiitothe satisfactoryutiln tl'ie particular eracking operation employed bfthe adgitive iniXtureibeauseitl1as been to. d Still furtl er present practices include blending t f oneonniqreof these 0 m" 0- f'io"1 iivith f V I apalilit y of thea clditive tisfac" 11;; in. a wide. vari ty t it 'a is tha achpm components eodperates with the ouier co'rnp'on mnar conta ns the co virgin and cycle stocks";

and is mutually dependent thereon for successful use in th manner herein intended.

The additive mixture includes the condensation product of a benzaldehyde and an alkanol amine containing from about 2 to about 12 carbon atoms per molecule. The benzaldehyde may contain alkyl substituent groups attached to the benzene mucleus but preferably does not contain a polar group (a group containing oXygen, nitrogen and/or sulfur) attached to the benzene nucleus as this substitution has been found to decrease solubility of the compound n fuel oils. On the other hand, the presenceof a hydrocarbon radical on the'benzene nucleus will increase solubility. The alkanol amine contains from about 2 to about 12 carbon atoms per molecule and, therefore, includes ethanol amine, propanol amine, butanol amine, hexanol amine, heptanol amine, octanol amine, nonanol amine, decanol amine, undecanol amine and dodeoanol amine.

The condensation of a benzaldehyde and an alkanol amine is readily effected at room temperature by mixing of the two reactants, preferably with stirring. The reaction is exothermic and provision may be made for cooling to absorb the heat of reaction. The products are then treated by distillation, preferably under vacuum, azeotropic distillation, solvent extraction or in any suitable manner to separate the water of reaction from the desired condensation p oduct. The second component of the additive mixture comprises an alkanol amine containing from about8 to about 40 carbon atoms per molecule and thus will include octanol amine, nonanol amine, etc. up to tetracontanol amine, or mixtures thereof. A particularly preferred alkanol amine for use in accordance with the present invention comprises the reaction product of ethylene oxide with an alkyl amine containing from about 10 to about carbon atoms per molecule. This reaction is readily effected at room or slightly elevated temperature, and the condensation product will generally contain several ethyl hydroxyl radicals which may vary from 2 to 20 or more. In place of ethylene oxide, other suitable alkylene oxides may be employed including propylene oxide, butylene oxide, etc. In general, it is preferred that the alkanol amine contains at least one branched chain grouping per molecule and also preferably comprises a mixture of at least two different alkanol amines. Another component of the additive mixture comprises an alkyl amine containing from about 6 to about 20 carbon atoms per molecule and thus includes hexyl amine, heptyl amine, octyl amine, etc. up to eicosanol amine or mixtures thereof. The alkyl amine preferably includes at least one branched chain grouping molecule and also preferably comprises a mixture of at least two different alkyl amines. I i

The next component in the additive mixture comprises a metal deactivator, which term is used to define a compound having the property of ofisetting the deleterious effect of metals-such as copper, vanadium, iron, cobalt, nickel, etc. to catalyze discoloration of the fuel oil. The metal deactivators are further defined as compounds capable of forming chelate compounds with the metals. A particularly preferred metal deactivator comprises the condensation product of an ortho hydroxy aromatic aldehyde with an alkylene polyamine. A particularly preferred metal deactivator is disalicylal diamino propane formed by the condensation of salicylaldehyde 4 and propylene diamine. Another satisfactory metal deactivator comprises the condensation product of salicylaldehyde with an o-aminophenol. Still another satisfactory metal deactivator comprises the tetra sodium salt of ethylene diamine tetraacetic acid and similar compounds. In general, it is preferred that the metal deactivator does not contain more than about 25 carbon atoms per molecule.

It generally-is preferred to utilize the additive mixture in a suitable solvent in order to insure complete solubility of the additive mixture in fuel oils. Any suitable solvent may be emp oy including alcohols, ketones, etc. A particularly preferred solvent comprises isopropanol.

The concentrations of the various components in the additive mixture may be varied over rather a wide range but, in general, will be within the following limits: from about 10% to about 50% by weight of the condensation product of a benzaldehyde and the alkanol amine, from about 10% to about 70% by weight of the alkanol amine, from about 10% to about 70% by weight of the alkyl amine, and from about 1 to about 20% by weight of the metal deactivator. solvent will generally be utilized in an amount of from about 10% to about 50% by weight of the additive mixture.

The additive mixture as hereinbefore set forth, will generally be satisfactory in a wide range of fuel oils. However, in some cases, it may be desirable to also include in the additive mixture an antioxidant and more particularly a phenolic antioxidant such as alkyl phenols, alkoxy phenols, alkyl-alkoxy phenols, amino phenols, naphthols, alkyl naphthols, alkoxy naphthols, alkyl hydroxy coumarans, etc. It is understood that a mixture of two or more different phenolic compounds may be employed. The phenolic compound, when employed, will generally be utilized in an amount of from about 10 to about 50% by weight of the additive mixture.

The additive mixture will be incorporated in the fuel oil in an amount of less than about 1% by weight of the fuel oil and more particularly in an amount of from about '0.0005% to about 0.1% by weight. It is understood that this additive mixturemay be utilized along with other additives added for a specific purpose as, for example, when'the fuel oil is to be used as diesel fuel, a cetane improver may also be incorporated in the oil.

Even with the multicomponent additive mixture of'the present invention, some fuel oils may not be completely responsive to treatment therewith. In such cases, it may be desirable to first subject the fuel oil to treatment with caustic. acid and/or clay treatment, and thereafter incorporate the additive mixture to the fuel oil. Treatment in this manner has been beneficial in some cases and, therefore, is included within the scope of the present invention.

In addition to the beneficial results obtained insofar as preventing discoloration of fuel oil, it has been observed that the additive mixture of the present invention also reduces sediment formatiori in fuel oils and this, therefore, provides a further advantage to thenovel additive mixture.

The following examples are introduced to i1- lustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.

The,

rue! oil usedin thisexmple was); ea-run oil 'comprising :catalytic uncle resultingrmm the-'erankmgoierlviid-confinentoil. 'l heafuel (li'1'1l1ad'lm.A.;P. I. gmvityatfifl Eliot 30.3, an initial boiling pointnt 4222 1". and an emdflaoilim' point of 603 F.

ililiscolorationof the tuel oil was determimdiin an accelerated test inwhich-difierenasamnles or thermal oil were placed m aconstant ture oil bath maintained at 212 F. and thermal determined .after as hours. The color W :detemrined by thexA. S. T. plmteelectrioeolor method as descrtbedin therAwiS.

' 6H";P&tf01fllllfl Products-and Lubricants, page M5,

(Detober 119447 edition. emelatesdairly well with long timestoragetests. as-will :be insome-of the following examples.

The additives used in following areasifollows: (A)- benzaiaminopropanol iormed by the condensation of benzaldehyde and isopropanol amine, GB?) an alkanol formed by the condensation of ethylene oxide with. a. mixture of alkyl amines .firom. about 16 to about l8 carbon atoms per molecule, (.6) an alkyl amineirazction -.comprising ami-x tune-oi alkyl .a-mines'containingz .irom about 8 to about Macarbonatoms per-molecule, and 1)) a metal deactioator comprising disalicylal- 'diamino propane termed by the condensation of. salicylaldehydeand 1,2-propylene In the interest of simplicity, these-additives will-be re terred tothe following table according to the letters indicated above.

Theadditive mixture of the present. invention, hereinaiter referred to as comprised, -.on a weight basis, approximately 211% A, .40% B, C, e% D and or asolvent comprising. isopropanol.

Before the start of the accelerated. test the fueloilhad an S. T. M. colorindex of .93. Bitferent asamples of. the oil were tested .inxtheaccelerated test described above, with the followingresults: .Each additive was nsedfinan amount From the above data it wodld-appear'thatadditi've B in itself would be satisfactory it retard discoloration of the fuel oil. However, fire particuiar sampleof the fuel oilnsed this example was free from metals. Upon the addi'tionoi a smallamount of copper to the 'fueloil, was noted. that. the. color index fell considerably. Therefore, another sample :of the fuel oilu containinglmetal'was tested *withaddiiiines Band D. This did :not prove: satisfactory as will by the data inrth'e following table. mso, vzamisous other combinations of additive B'- with the other-additives were tried, :and these resnlts aaxe also shown in the iollowmg table, :as- "well as the results of additivesat and B and of additive .Each additive was' used iman-amomrt or 0203 x; weight.

A. S. 'l. M.

Additive Photoelectric Color Index From data; the above table, it is apparcut that additive mixture .E .is better than the other combinations tested. As hereinbefore set forth, additive mixture E is also more desirable becauseet tits satisfactory use in a wide variety oi tlifierent fuelv oils.

EXAMPLE II Table 3 A. s. 'r. M.

Additive Photoelectric Color Index None 22 A l 13 6 v3 65 lowing table: The additives were employed in an amount of 0.05% by'weight.

Table 4 A. S. T. M. Photoelectric Oblor'Iniiex Additive Here again, it'- Wiilbe-noted that additive mixture E was considerably "better than the indi vidual components.

EXAMPLE/IV example shows the results of acid treatme: of: theinel oil the incorporation of additives. .Anortion of. "the fuel oil was treated withfiipoumls of. 98% :sullfiuric .acid :at room temperature. Theresultsaoaf the accelerated testsv of :diflerent samplesm the-.fuelroil, with-and without acid treatment, andwith and without additives are shown in the following table:

Table .4. s. 'r. M. Photoelectric Color Index Additive Acid Treated Fuel Oil Untreated Fuel Oil None 0.5 0.05% Additive En 2. 2 79. 9

It will be noted that with this particular fuel oil response to additive E was considerably improved by previous mild acid treatment.

A. S. T. M. Photoelectric @010! Index Additive None 0.05% Additive E It will be noted that the sample fuel oil without additive dropped in color index from 96.5 to 77.4 and that use of the additive maintained the color at 93.

The fuel oil used in this example was a mixture of 50% virgin gas oil and 50% catalytic cycle stock. The blended fuel oil prior to storage, had a color index of 95. The following table shows the results of both the accelerated test and after storage at 100 F. for 22 days.

Table 7 A. S. T. M. Photoelectric Oolor Index Additive Storage I Accelerated Test Test None 0.05% of Additive E It will be noted that additive mixture E. served effectively to retard discoloration of the blend of virgin and cycle stocks. Further, this example illustrates the satisfactory correlation of the accelerated test with the actual storage test of 22 days. 5

We claim as our invention:

1. A fuel oil heavier than gasoline containing from about 0.0005% to about 1.0% by weight of an additive mixture comprising (1) from'labout 10% to about 50%by weight-of a benzalaminoalkanol in which the alkanol group contains from about 2 to about 12 carbon atoms per molecule, (2) from about 10 to about 70% by weight of an alkanolamine containing from about 8 toabout 7 5 40 carbon atoms permolecule, (3) from about 10 to about 70% by weight of an alkyl amine containing from about 6 to about 20 carbon atoms per molecule and (4)"from about'l to about 20% by weight of'a 'metal deactivator comprising a compound "capable of forming chelate compounds withmetals.

2. The composition of claim 1 further characterized in that said additive mixture also contains a phenolic antioxidant in an amount of fromabout 10 to" about 50 by Weight of said mixture. i

3. The composition of claim'l further characterized in-that said metal deactivator comprises disalicylal diamino propane.

4'. A fuel oil heavier than gasoline containing from about 0.0005% to about 1.0% by weight of an additive mixture comprising (1) from about 10% to about 50% by weight of a benzalaminoalkanol in which the alkanol group contains from about 2 to about 12 carbon atoms per molecule, (2) from about 10 to about 70% by weight of an alkanol amine containing from about 8 to about 40 carbon atoms per molecule, (3) from about 10 to about 70% by weight of an alkyl amine containing from about 6 to about 20 carbon atoms per molecule, (4) from about 1 to about 20% by weight of a metal deactivator comprising a com pound capable of forming chelate compounds with metals and (5) from about 10 to about 50% by weight of a solvent comprising isopropanol.

5. A fuel oil heavier than gasoline containing from about 0.0005% to about 0.1% by weight of an additive mixture comprising (1) from about 10% to about 50% by weight of benzalaminopropanol, (2) from about 10 to about 70% by weight of an alkanol amine containing fromabout 8 to about 40 carbon atoms per molecule, (3) from about 10 to about 70% by weight of an alkyl amine containing from about 8 to about 14 1 carbon atoms per molecule, (4) from about 1 to about 20% by weight of disalicylal diamino propane and (5) from about 10 to about 50% by weight of isopropanol.

6. The composition of claim 5 further char-- acterized in that said additive mixture also contains a phenolic antioxidant in an amount of from about 10 to about 50% by weight of said mixture.

p '7. A fuel oil heavier than gasoline containing a stablizing amount of an additive mixture comprising (1) from about 10% to about 50% by weight of'a benzalaminoalkanol in which the alkanol group contains from about 2 to about 12 carbon atoms per molecule, (2) from about 10 to about 70% by weight of an alkanol amine containing from about 8 to about 40 carbon atoms per molecule, (3) from about 10 to about 70% by weight of an alkyl amine containing from about 6 to about 20 carbon atoms per molecule and (4) from about 1 to about 20% by weight of a metal deactivator comprising a compound capable of forming'chelate compounds with metals.

: 8. The composition of claim 7 further characterized in that said metal deactivator comprises disalicylal. diamino propane.

9; A stabilizing composition suitable for preventing discoloration of fuel oils comprising (1) from about 10% to about 50% by weight of a benzalaminoalkanol in which the alkanol group contains from about 2 to about 12 carbon atoms per molecule, (2) from about 10 to about 70% by weight of an alkanol amine containing from about 8'to about40 carbon atoms per molecule,

' (3) from about 10 to about 70% by weightof an- 9 alkyl amine containing from about 6 to about 20 carbon atoms per molecule and (4) from about 1 to about 20% by weight of a metal deactivator comprising a compound capable of forming cheiate compounds with metals.

10. The composition of claim 9 further characterized in that said metal deactivator comprises disalicylal diamino propane.

RALPH B. THOMPSON. JOSEPH A. CI-IENICEK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Rather et a1 Jan. 29, 1935 Rogers et a1 Feb. 19, 1935 Downing eta-l May 12, 1942 White et a1. Nov. 3, 1942 Chenicek Apr. 18, 1944 White et a1. Oct. 24, 1944 

1. A FUEL OIL HEAVIER THAN GASOLINE CONTAINING FROM ABOUT 0.0005% TO ABOUT 1.0% BY WEIGHT OF AN ADDITIVE MIXTURE COMPRISING (1) FROM ABOUT 10% TO ABOUT 50% BY WEIGHT OF A BENZALAMINOALKANOL IN WHICH THE ALKANOL GROUP CONTAINS FROM ABOUT 2 TO ABOUT 12 CARBON ATOMS PER MOLECULE, (2) FROM ABOUT 10 TO ABOUT 70% BY WEIGHT OF AN ALKANOL AMINE CONTAINING FROM ABOUT 8 TO ABOUT 40 CARBON ATOMS PER MOLECULE, (3) FROM ABOUT 10 TO ABOUT 70% BY WEIGHT OF AN ALKYL AMINE CONTAINING FROM ABOUT 6 TO ABOUT 20 CARBON ATOMS PER MOLECULE AND (4) FROM ABOUT 1 TO ABOUT 20% BY WEIGHT OF A METAL DEACTIVATOR COMPRISING A COMPOUND CAPABLE OF FORMING CHELATE COMPOUNDS WITH METALS. 